SDL_thread.h File Reference

The SDL thread priority.

Note:

On many systems you require special privileges to set high priority.

Definition at line 59 of file SDL_thread.h.

The function passed to SDL_CreateThread().

It is passed a void* user context parameter and returns an int.

Create a thread.

Create a thread.

Thread naming is a little complicated: Most systems have very small limits for the string length (Haiku has 32 bytes, Linux currently has 16, Visual C++ 6.0 has nine!), and possibly other arbitrary rules. You'll have to see what happens with your system's debugger. The name should be UTF-8 (but using the naming limits of C identifiers is a better bet). There are no requirements for thread naming conventions, so long as the string is null-terminated UTF-8, but these guidelines are helpful in choosing a name:

http://stackoverflow.com/questions/149932/naming-conventions-for-threads

If a system imposes requirements, SDL will try to munge the string for it (truncate, etc), but the original string contents will be available from SDL_GetThreadName().

A thread may be "detached" to signify that it should not remain until another thread has called SDL_WaitThread() on it.

Detaching a thread is useful for long-running threads that nothing needs to synchronize with or further manage. When a detached thread is done, it simply goes away.

There is no way to recover the return code of a detached thread. If you need this, don't detach the thread and instead use SDL_WaitThread().

Once a thread is detached, you should usually assume the SDL_Thread isn't safe to reference again, as it will become invalid immediately upon the detached thread's exit, instead of remaining until someone has called SDL_WaitThread() to finally clean it up. As such, don't detach the same thread more than once.

If a thread has already exited when passed to SDL_DetachThread(), it will stop waiting for a call to SDL_WaitThread() and clean up immediately. It is not safe to detach a thread that might be used with SDL_WaitThread().

You may not call SDL_WaitThread() on a thread that has been detached. Use either that function or this one, but not both, or behavior is undefined.

It is safe to pass NULL to this function; it is a no-op.

Get the thread identifier for the specified thread.

Equivalent to SDL_ThreadID() if the specified thread is NULL.

Get the thread name, as it was specified in SDL_CreateThread().

This function returns a pointer to a UTF-8 string that names the specified thread, or NULL if it doesn't have a name. This is internal memory, not to be free()'d by the caller, and remains valid until the specified thread is cleaned up by SDL_WaitThread().

Set the priority for the current thread.

Get the thread identifier for the current thread.

Create an identifier that is globally visible to all threads but refers to data that is thread-specific.

Returns:

The newly created thread local storage identifier, or 0 on error

  static SDL_SpinLock tls_lock;
  static SDL_TLSID thread_local_storage;
 
  void SetMyThreadData(void *value)
  {
      if (!thread_local_storage) {
          SDL_AtomicLock(&tls_lock);
          if (!thread_local_storage) {
              thread_local_storage = SDL_TLSCreate();
          }
          SDL_AtomicUnLock(&tls_lock);
      }
      SDL_TLSSet(thread_local_storage, value);
  }
  
  void *GetMyThreadData(void)
  {
      return SDL_TLSGet(thread_local_storage);
  }

See also:

SDL_TLSGet()

SDL_TLSSet()

Get the value associated with a thread local storage ID for the current thread.

Parameters:

id	The thread local storage ID

Returns:

The value associated with the ID for the current thread, or NULL if no value has been set.

See also:

SDL_TLSCreate()

SDL_TLSSet()

Set the value associated with a thread local storage ID for the current thread.

Parameters:

id	The thread local storage ID
value	The value to associate with the ID for the current thread
destructor	A function called when the thread exits, to free the value.

Returns:

0 on success, -1 on error

See also:

SDL_TLSCreate()

SDL_TLSGet()

Wait for a thread to finish.

Threads that haven't been detached will remain (as a "zombie") until this function cleans them up. Not doing so is a resource leak.

Once a thread has been cleaned up through this function, the SDL_Thread that references it becomes invalid and should not be referenced again. As such, only one thread may call SDL_WaitThread() on another.

The return code for the thread function is placed in the area pointed to by status, if status is not NULL.

You may not wait on a thread that has been used in a call to SDL_DetachThread(). Use either that function or this one, but not both, or behavior is undefined.

It is safe to pass NULL to this function; it is a no-op.